高填充碳酸钙母料在LLDPE薄膜中的应用

将高填充碳酸钙母料用于线型低密度聚乙烯(LLDPE)薄膜,研究了碳酸钙粒径、填充量及分散树脂对薄膜加工流动性和力学性能的影响.结果表明,高剪切速率下碳酸钙粒径对LLDPE黏度影响不大,但粒径细化提高了薄膜力学性能;以聚烯烃弹性体(POE)作为分散树脂可以提高薄膜加工流动性,改善碳酸钙分散均匀性;碳酸钙填充量增加导致加工流动性下降;选择粒径为5.5μm的碳酸钙和POE制备填充母料,LLDPE薄膜即使在质量分数30%碳酸钙下仍具有较好的加工性能和力学性能.     

芦苇纤维/废旧聚乙烯复合材料的研究

采用芦苇纤维填充废旧聚乙烯,研究了芦苇纤维偶联处理、增容剂用量、芦苇纤维用量、芦苇纤维粒径大小对复合材料性能的影响。结果表明,偶联剂用量为芦苇纤维用量的1.3%(质量分数)左右、增容剂为15份时复合材料综合性能最佳,随芦苇纤维用量的增加和粒径的增大会使复合材料拉伸强度、冲击强度下降。     

高填充碳酸钙母料的流变行为

采用平板式旋转流变仪研究了碳酸钙粒径及填充量、分散树脂种类及用量、温度对高填充碳酸钙母料流变性能的影响。研究发现,填充母料的流变曲线出现两个“剪切变稀”区域,分别与低剪切速率下填料与树脂间的结合破坏和高剪切速率下分子链缠结破坏及链段取向有关;母料的零剪切薪度远高于线形低密度聚乙烯( PE-LLD),且随碳酸钙粒径细化和含量的增加而迅速增大;填充母料“剪切变稀”行为比PE-LLD更加明显,导致在102一103 s-1剪切速率范围内母料与纯树脂的表观薪度比较接近;高剪切速率下碳酸钙粒径对表观薪度影响不大,添加分散树脂明显降低了填充母料的表观薪度;母料的流动活化能为25.7目/mol,与PE-LLD的相近。     

聚乙烯透湿保鲜膜的研制与性能研究

利用钛酸酯偶联剂对轻质碳酸钙进行表面改性,将改性后的碳酸钙添加到LDPE基体中,制备透湿性薄膜.测试了该保鲜膜的拉伸强度,热合强度以及透湿性能.结果表明:当钛酸酯偶联剂TC-2的质量分数为2%时,碳酸钙可达95%的活化度.LDPE中添加碳酸钙可在薄膜中引入无数微小的缺陷,从而制得透湿性能较好的薄膜.从薄膜的力学性能、透湿性能综合考虑,碳酸钙的用量为20份时,保鲜膜性能最佳.     

一种高分散、高填充、无载体纳米碳酸钙母料的制备

通过在纳米碳酸钙悬浮液中加入解聚偶联剂,并在干燥好的物料,通过气流碎机解聚时,同时加入解聚偶联剂的方法,制得高分散纳米碳酸钙;加入各种塑料功能助剂,提高与高聚物的相容性,并制成高分散高填充无载体母料。可以满足各种塑料和橡胶聚合物的加工,作为补强剂及填充剂,特别是应用于高档的ABS和PC等工程塑料,补强性能优秀。     

滑石粉填充聚乙烯母料的流变性能研究

采用毛细管流变仪研究了不同剪切速率下分散剂种类及用量、加工温度、滑石粉含量及粒径以及偶联剂含量对滑石粉填充聚乙烯母料流变性能的影响。结果表明,聚乙烯母料的流变曲线出现"剪切变稀"行为;聚乙烯母料的黏度随分散剂含量增加以及加工温度升高而降低;聚乙烯母料的黏度随母料中滑石粉含量增加而迅速增大;滑石粉粒径减小和偶联剂含量增加使聚乙烯母料的黏度略有下降。     

丁腈橡胶/硼酸酯偶联剂改性纳米碳酸钙复合材料的性能

用硼酸酯偶联剂对纳米碳酸钙进行表面改性,研究了丁腈橡胶(NBR)硼/酸酯偶联剂改性纳米碳酸钙复合材料的性能。结果表明,使用硼酸酯偶联剂改性纳米碳酸钙填充NBR能提高硫化胶的物理机械性能,当硼酸酯偶联剂用量为4份、改性纳米碳酸钙用量为75份时,硫化胶的综合性能最好;与未改性纳米碳酸钙填充NBR相比,硼酸酯偶联剂改性纳米碳酸钙填充的NBR混炼胶和硫化胶的弹性模量较小,Payne效应减弱,而损耗因子却较大;用硼酸酯偶联剂改性纳米碳酸钙填充NBR,化学交联质量分数提高,无机粒子与橡胶基体之间的化学结合作用增强。     

PP静音芯层料的制备与性能

以聚丙烯(PP)为基体树脂,BaSO_4为无机填料,铝酸酯为偶联剂,通过共混法制备了硫酸钡填充聚丙烯静音复合母料,研究了不同添加量(质量分数)的BaSO_4、铝酸酯对静音母料的密度、拉伸强度、冲击强度、熔体流动速率、维卡软化温度的影响,同时也对比了2种交联助剂、内外润滑剂对静音母料的影响效果。结果表明:当硫酸钡的添加量为70%~75%时,静音母料的密度达到了行业标准的要求,并且静音母料的拉伸强度、冲击强度、熔体流动速率、维卡软化温度都比纯树脂聚丙烯(PP)有所提高。偶联剂、交联助剂、内外润滑剂都有助于提高静音母料的综合性能。     

改性CaCO3填充PE母料的研制及应用

研究了CaCO_3填充聚乙烯母料中的复合偶联剂、复合分散剂及母料加入量对填充母料体系力学性能和流变性能的影响,并介绍了填充母料在周转箱中的应用。     

纳米无机材料在高填充MS胶中的应用

以非介入式材料均质机为搅拌抽真空设备,采用L9(33)三因素三水平正交实验分析了分散工艺参数对高填充硅烷改性聚醚密封胶(MS胶)黏度的影响;研究了不同粒径碳酸钙复配及埃洛石纳米管(HNTs)对高填充MS胶性能的影响。结果表明,在公转速率为1 000 r/min、自转速率为公转的80%、搅拌时间为2 min条件下制得的MS胶黏度较低;纳米碳酸钙、亚微米碳酸钙、微米碳酸钙质量比为4∶1. 5∶1. 5时,体系的拉伸强度、拉断伸长率、拉伸剪切强度均达到最大值; HNTs对高填充MS胶有显著的增稠及增强效果,当HNTs(相对于体系总质量)质量分数为5%时,体系的拉伸剪切强度、拉伸强度、拉断伸长率均达最大值,分别为1 413 k Pa、1 866 k Pa和265%。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。